2015 Suzuki df20 runs rough 5 minutes (after red light turns on), dies

[jpan28]

Was able to "get by" all day, just couldn't go anywhere fast and had to start again every 5 minutes. Don't think its overheating, as the telltale is shooting plenty of water. Tried two different tanks, both with fresh gas and well vented. Seems to only happen in forward gear:
1. Starts fine (electric start)
2. Put in forward gear
3. Runs fine for a few seconds (even seems to accelerate normally if I open up the throttle)
4. Red light suddenly turns on at the same time that it starts running super rough
5. Runs rough for about 5 minutes, not letting me go very fast, but still pushing the boat a bit
6. Turns off
7. Rinse and repeat...

Oh, and although it's been sitting for a few months, it was checked out by a Suzuki mechanic and changed the oil before it sat. Gas had stabilizer. Any ideas would be greatly appreciated. It's a 2015 model

[Murray]

Gas had stabilizer, but was the engine ran for 15 minutes to distribute the fuel throughout the fuel system? Tell us more about this red light, flashing a code or a solid red light? How’s the battery, full charge and in good shape? This issue wasn’t present when you parked the boat?

[Moonlighter]

Re the possible overheating, these engines have 2 temp alarms -

One is an absolute alarm where when the temp gets too high and reaches a preset warning level, the alarm activates.

The other is a gradient alarm, where if the temp increases too rapidly but may not reach the absolute alarm temp, the alarm sounds. You may be getting the gradient alarm. This can happen when the thermostat is not working properly or the water pump impeller developed a set or the vanes have hardened.

Hooking the engine up to the Suzuki Diagnostic System would show the history of alarms and identify which one it was each time. It would also identify what the alarm was if it was not temp related.

Also as Murray indicated, a battery in poor condition or not charged up, or corroded wiring/connections, will contribute to low voltage at the ecu and may be the cause if false alarms.

[jpan28]

Thanks for the responses. Battery was fully charged. The red light was solid. Issue was not present when I parked the boat. I'd like to acquire the SDS tool, but its confusing which one will work on the DF20. Will this one (on Amazon) work? https://www.amazon.com/moto-solution...8340708&sr=8-4
Thanks again

[Murray]

I checked your link to Amazon, page 2 of 3 last question in the “Customer Questions and Answers” according to seller it will not work with DF20A, only good for 40hp and up. I’m not familiar with your engine, I was thinking your alarm light would be flashing a code to help pin point the issue, a solid light I’m not familiar with. All I can suggest is check all the electrical plugs, maybe the mechanic who changed the oil inadvertently knocked a plug loose causing you the alarm. Did you check the oil level? Moonlighter has indicated it might be overheating. When was the last time the impeller and water pump housing changed? If your water pump is original I would suggest you change that out, it’s not too expensive parts wise, I can do mine DF90A for $70 Canadian. I would also suggest you get a genuine Suzuki service manual if you choose to do the work yourself. The service manual will have all the testing procedures and locations of the sensors. Sorry I couldn’t be more help, hopefully some of the other members more familiar with your engine will chime in. Good luck.

[jpan28]

The vendor said he didn't "think" it would work because those smaller engines don't have an ECU. However, I believe they do have one (at least mine does). The motor is practically new with less than 20 hours on it. Thank you for your suggestions.

[Murray]

Suzuki were offering a 6 year warranty, wondering if your engine qualifies?

[jpan28]

My warranty was 3 years, as far as I know

[Hoosmatroos]

Do you have a picture of the engine block?

[jpan28]

Not there yet, but on my way to solving this problem... Purchased the SDS (diagnostic kit) from Amazon for about $65. It does work on the DF20. The only catch is that the motor has to be running for the ECU to have power to communicate with the software. There were no fault codes. A mechanic friend told me it's likely a fuel issue, so I'm concentrating there. Will change the filter and also removed another filter I had in-line on the fuel hose. Also ordered some spark plugs. I'll keep everyone posted.

[2014DF25ARS]

I'm not familiar with the DF20, but I have a DF25A and encountered an issue that feels similar. Is the DF20 a fuel-injected motor? On my DF25A, I reached a point where it would start without problems and begin accelerating, but then "bog down" to an idle. Eventually I fixed the problem by replacing the fuel filter that sits in front of the high-pressure fuel pump. This is NOT the large blue water-separating fuel filter that's obvious. It is a smaller black in-line filter which on my engine is buried beneath some fuel hoses. I have the SDS tools, and in my case the engine was not throwing any codes. But what I concluded is that this filter may have been clogged to the point of starving the high-pressure pump of fuel when high RPMs (and thus fuel flow) are called for.

A mechanic told me that a common problem with folks when they first move to a fuel-injected engine is that at the end of the day they will disconnect the fuel line and run their engines dry, like they were accustomed to doing with carbureted engines. THIS IS A BIG NO-NO WITH FUEL INJECTED MOTORS. Problem is that the high-pressure fuel pump relies on fuel flow to cool the pump, so if you run one dry it can quickly destroy the pump. For this reason, I theorize that the pump may send a signal to the ECU when fuel pressure drops, to idle the engine and avoid destroying the fuel pump. And maybe that condition isn't captured by the diagnostics - although that would seem like a pretty big oversight to me.

My issue didn't occur until around 150 hrs of use. It seems a bit unlikely that you would see it at only 20 hrs. But it also seems unusual that you have a 2015 motor with only 20 running hours on it. So maybe it has spent some long period of time with fuel sitting in it, gumming up that filter. I remember describing my problem a year or two ago to someone else on this forum, so you could search my posts here for more detail about the filter.

[artdf175]

I tried looking back through this string
I may have missed it but have you gone through the fuel delivery system?
Tank venting is a problem
the fuel connection to the tank -- there is an anti-siphon ball bearing they valve that often impedes fuel flow
the fuel bulb can create problems sitting not in a vertical position
the fuel bulb has been known to be reversed - fuel flows only one direction
and all the connections need to be checked so no air can be sucked into the system
when you have a problem have you observed the fuel bulb? Flat? only partially filled and have to pump it more than once to get fuel pressure?
The running five minutes and then the problem starts is kind of a classic fuel type problem Either you are running all the fuel out or air is getting into the system
Art

[D'oh999]

Fuel Delivery would not cause the Red Warning Light.

running rough as in Fail Safe Mode? Then Full Shut Down? Like a low oil pressure/level, water flow/temp?

[jpan28]

Motor had previously been run with an ethanol fuel mix, so I've now changed out the gas to get rid of the ethanol, changed the fuel filter, and got rid of an extra "in-line" filter on the gas line. As I mentioned, there are no fault codes. Also bought a pair of spark plugs in case I need them. Planning to test it this weekend just with the fuel changes. Keeping my fingers crossed. Tanks have been vented and I'll keep an eye on the fuel bulb. Still don't know the rules governing the red light turning on.

[artdf175]

the red warning light could be low voltage
the shutting down without a triggering a fault code is not a fail safe- which would normally just reduce rpm
Jpan- you need to keep the small inline filter in place
the main reason is to help you watch the fuel flow
without it you have no chance of knowing if air is leaking into the fuel system prior to the low pressure fuel pump
Art